The International Agency for Research on Cancer has coordinated a multi-national prospective case-control study of cellular telephones and cancer risk. The INTERPHONE study was conducted in 13 countries using a common core protocol, and focused on the risk of glioma, meningioma, acoustic neurinoma and parotid gland tumors. A total of 2,613 glioma and 2,343 meningioma cases and 7 557 controls were recruited between 2000 and 2005, making INTERPHONE the largest analytical epidemiological study of brain cancer ever conducted. The current proposal aims to exploit the information on occupational exposures collected within the INTERPHONE study. It has three specific aims: 1. To evaluate the possible association between the occupational exposure to EMF and tumors of the brain and central nervous system (specifically, glioma and meningioma). 2. To evaluate the possible association between selected occupational chemical exposures and tumors of the brain and central nervous system (specifically, glioma and meningioma). 3. To investigate the possibility of synergism and/or confounding between chemical and EMF exposures on the risk of brain cancers. In order to achieve these substantive aims we will need to address the following operational objectives: To transform the occupational history and questionnaire data into meaningful indices of EMF. To devise and implement methods for transforming job histories into occupational chemical exposure information. Occupational exposure to EMF (both ELF and RF/MW) and selected chemicals will be assessed for all the study subjects using validated job-exposure matrices, which will be developed within this project. The assessment of EMF exposure will then be refined by consolidating information obtained from the JEM with data on exposure variations related to the specific industry in which a subject worked, to the tasks he or she performed and to the actual sources of exposure, available from the INTERPHONE questionnaire. For chemicals, the JEM based estimates will be compared to estimates derived by occupational hygienists using the more detailed occupational histories in Canada, France, New Zealand and the UK, thereby providing an indication of the validity of the classification. Finally, analyses of the relationship between brain tumor risk and exposure to EMF and to the chemicals of interest will be carried out. Further analyses of possible interactions between EMF and specific chemicals will also be conducted.